Hand-operated blade grinder



Apk-ii 16, 1940 G. BARscH HAND-OPERATED BLADE GRINDER Filed Nov. 10. 1957 ,Z''venian @Uuml/M5 5,4/356/1 y Wa S.

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Patented Apr. 16, 1940 PATENT or-'FICE HAND-OPERATED BLADE GRINDER vGuillaume Barsch,

Luzern, Switzerland Application November 10, 1937, Serial No. 173,748

- InI Germany November 12, 1936 8 Claims.

It is an object of this invention to provide a f "l54 machine of this kind, the construction of which will be very simple and cheap in production and assembly and the efficiency of which will be very high. v

Further objects" of the invention will be clear from thefollowing detailed description of the invention.

According to ,the invention the device cornprises rotating vgrinding wheels in tandem arrangement vand means adapted to rotate the grindingl wheels by the reciprocating movements of the blade between the grinding wheels in the grinding action. These means include a gear system adapted to-convert the reciprocating movement of the knife blade into a rotating movement. The conversion of thereciprocating movement of the knife to be sharpened into a rotating movement according to this invention may be effected for instance in such` a manner that the knife blade which is to be moved between thegrinding 25 wheels is guided? between friction wheelsor the like which engage the knife blade 'from opposite sides and the rotationof which is transferred, by means of one shaft each and further friction Wheels, toothed wheels or the like, upon, the

30 grindingwheels. It is not necessary for the friction wheels to engage the knife blade directly, but the device may be so provided that the friction wheels or the like engage a reciprocating guiding bar serving-as a blade holder'.` vIn this case, the friction wheels are preferably replaced by toothed wheels or pinions and the reciprocating bar of the knife holder is preferably formed as a toothed rack engaged by said pinions.

Further features of the invention will be clear 40 from 4the followingdetailed description of the drawing, showing by` way of .example and schematically some embodiments of the invention, lv1z.--

Figure 1 is an inside view of an 45 4of my novel grinding device; f

Figure 2`is an inside view of a modified form, the casing being partly broken away; I

Figure 3 is a plan view of Figure 2.

In each of the embodiments shown in 'the drawing, two grinding Wheels I are arranged side by side with parallel aires,` partly. overlapping eachother. In order to introduce the blade between the grinding wheels I,-the casing 2 has recesses 3 'which are reduced. in-width towards the bottom.` In each of the'y said embodiments, moreembodiment over, the grinding wheels are rotated'by the reciprocating movement of the knife Yblades between the grinding wheels. Identical reference numerals have been used in the different figures to denote identical parts. TA5 Referring to Figures 1 to 3, thel knife blade 4 is engaged on both sides by friction wheels 5, for instance of rubber, which transmit their rotation caused by the rocking or reciprocating movement of the knife blade upon the grinding i wheels I, through shafts 6. According to Figure 1, the grinding wheels I have toothed rims 'I engaging the toothed wheels or pinions 8 of the driving lshafts 6. One of the two toothed wheels 8 engages the upper part of the toothed rim 'I of its coordinated grinding wheel and the other' toothed wheel 8 engages the lower portion of the toothed rim of the' other grinding wheel, thus producing a rotation of the two grinding wheels in the same direction.' Accordingly one of the two grinding `wheels acts against the blade A,and the other grinds ";ff the blade. This direction of rotation of the two grinding wheels I changesv with each reversal Aof the movement of the knife blade 4. `The friction wheels are formed as .endknobs or caps ofthe obliquely arranged driving shafts 6 which are mounted at their lower end-in bent olf tongues 9 of the casing 2 and at their upper ends' in plates II. The plates II aregswingable in a horizontal direction roundl pivots I2v and are. acted upon by springs I3 which tend to press the knobs 5 together or against. the knife blade 4, respectively. Thus, the knobs '5,v the .driving shafts 5 and the Agrinding wheels I will be driven' by the knife blade Il when it is reciprocated by'hand in the grinding action The two grindingwheels I are mounted,I according` to Figure l., on two swingable levers or plates in v such a mannerthat the grinding angle depends on the pressure exerted during the grinding movement upon the knife blade. It will be seen that only one of the swingable `plates serving as a support of one ofthe grinding wheels has been shown, that is to say the plate I4 which is swingable'round the pivot I5 and acted upon by a spring I6 which tends to hold the plates and thus the grinding wheels I in their extreme upper lpositions. v

The second plate which serves as a support for the second grinding wheel and is caused to fol- 50 low the movement of plate I4 by a guiding slot and a pin engaging said slot, under action of spring I6, is covered and not visible.

It will beiunderstood that by exerting a greater pressure upon the* knife lblade d in the'grinding 55 the grinding wheels i.

action, the grinding wheels are depressed against action of spring I6, whereby the grinding angle is increased. It is also possible to adjust a predetermined grinding angle before grinding. To this end, the plate Ul is formed with a bentoff portion I'F in the form of a handle by which the plates with the grinding wheels can be swung by hand into any desired position and held in `this position during the grinding action. A

pointer I8 provided at the bent-off portion ll' permits of adjustment of a predetermined grinding angle on a scale I9 gauged according to grinding angles.

I contemplate to provide rests or. arresting means between pointer I3 andscale I9 so as to hold the handle Il mechanically in a predetermined position.

According to Figures 2 and 3, the reciprocating movement of the knife blade'upon the grinding wheels i is transmitted upon the grinding wheels l substantially in the manner shown in Figure 1 except differences in the detailsy of construction. Thus, the grinding wheels ll in this instance do not have the same direction of rotation, but run in opposite directions and grind against the edge. However, when the movement of the knife blade is reversed, the direction of rotation of the grinding wheels is not changed, but the wheels maintain their (opposite) directions of rotation. To this effect, the driving shafts 6 are arranged swingable or tiltable around pivots 2l supported in bent-off tongues 2li of the casing. Moreover, the driving shafts 6 are provided with two toothed or friction wheels 22 each in order to transmit the rotation of the end knobs 5 and shafts 6 upon The members 22 are so arranged that with one stroke of the-knife blade the lower toothed or friction wheel22v and with the opposite stroke the upper toothed or friction wheel 22 will automatically engage the lower portion or the upper portion, respectively, of the toothed friction rim 23.

Figure 3 indicates one extreme position ofthe swingable driving shafts 6. It willbevunderstood that the end knobs 5 will move in the direction of the arrow 2Q to their opposite extreme position when the moving direction of the knife blade is reversed and vice versa. In order to render possible the alternating rocking ofthe driving shafts 6, the two ends thereof are supported in slots oi' the spring-acted plates Il and inv slots of the tongues 9.

While I have herein shown and described certain preferred embodiments of my invention, I wish it to be understood that I do not confine myself to all the precise details herein set forth by way of illustration, as modification and variation may be made without departing from the spirit of the invention or exceeding the scope of the appended claims.

I claim:

1. In a grinding machine; a pair of grinding wheels adapted to sharpen knife blades which arey opposite portions of a drive-transmitting rim on' a lateral face of said grindingfwheels, by swinging movement of said shaft caused by the reciprocating movementsv of said knife blade, whereby the said friction wheels are driven in a continnous direction by the reciprocating movement of said knife blade.

both sides' of a 4blade when the edge of the latter engages the grinding wheels, and means for transmitting to the grinding wheels a rotatingy movement'impart'ed .to the friction wheels by the reciprocated'blade. c

3. Ina grinding device, at least a pair of grinding wheels rotatable in parallel planes and having axes parallel to and on opposite sides of a center plane, a segment of each wheel protruding beyond said center plane, a pair of friction wheels associated'with said grinding wheels respectively, said friction wheels having axes in an identical plane perpendicular to said center plane, and being arranged close to each other and at the same sides of said center plane as the associated grinding wheels., so. as to "be simultaneouslyY in frictional engagement-with both sides of a blade reciprocated in said center plane when the edge of said blade engages said grinding wheels, and means for transmitting to the grinding wheels a rotating movement` imparted to said friction wheels by the reciprocated blade.

4. In a grinding device, at least onev pair of grinding wheels having axes parallel to andy on opposite sides ofa central plana-and having' cylindricalgrinding surfaces, said grinding wheels being adapted to simultaneously sharpen both sides of a blade-edge reciprocated in said center piane between said cylindrical surfaces, a pair of friction wheels associated with said grinding wheels respectively, said friction wheels being' arranged on the same sides of said central plane as the associated grinding wheels, 'means for urging `said friction vwheels towards each other, and ,y means for .transmitting to the grinding wheels a to the axes of said grinding wheels so as'to rotate both said grinding wheels in the same direction' when' the driving wheels rotate in opposite directions tofeach other owing to the rotating move-- ment impartedto the friction wheels by the movement ofsaid blade' reciprocating between the friction wheels. n

6. In a grinding device, at least one .pair of grinding ywheels arranged with their axes parallel to and on opposite sides'of va central'plane'so as to overlap each other partly, means for selectively adjusting the .distance of said parallel axes' from eachY other, a pair of. friction wheels associated with said grinding wheels respectively,y said friction wheels being arranged onv-th'e ysame vsides of said central plane as the associated grinding wheels, means for urging said friction Wheels tothe distancey of said grinding wheels from each other, a pair of friction Wheels associated with said grinding Wheels respectively, said friction Wheels being arranged on the same sides of said Central plane as the associated grinding Wheels,

, means 'for' urging ysaid friction Wheels towards each othergand means for transmitting'to the grinding wheels a rotating movement yimparted to the friction Wheels by a blade inserted and re-.

ciproeatevd between said friction Wheels.

8. In a grindingdevice as claimed in claim 7,

a pointer at said lever and a scaleopposite said. pointer to indicate the grindingangle between said overlapping grinding wheels. l.

GUILLAUME BARSCH. 

